1. Field of Invention
This invention relates to performing transactions over a computer network. More particularly, it relates to performing retail client/server transactions on the internet using the Hypertext Transfer Protocol (HTTP).
2. Background--Description of Prior Art
For fifty years, people have dreamed of the concept of a universal information database--data that would not only be accessible to people around the world, but information that would link easily to other pieces of information so that only the most important data would be found by a user. Only now has technology caught up with these dreams, making it possible to implement them on a global scale. This global system is called the World-Wide Web or WWW.
The WWW began in March 1989, when Tim Berners-Lee of CERN (a collective of European high-energy physics researchers) proposed the project to be used as a means of transporting research and ideas effectively throughout the organization.
Months after CERN's original proposal, the National Center for Supercomputing Applications (NCSA) began a project to create an interface to the World-Wide Web. One of NCSA's missions is to aid the scientific research community by producing widely available, non-commercial software. The NCSA's Software Design Group began work on a versatile, multi-platform interface to the World-Wide Web and called it Mosaic.
The use of Mosaic during the second half of 1993 and 1994 has been growing rapidly. There are now millions of copies distributed on computers all over the world.
The Web works under the popular client-server model. A web server is a program running on a computer whose only purpose is to serve documents to other computers when asked to. A Web client is a program that interfaces with the user and requests documents from a server as the user asks for them. Here is an example of how the process works:
1. Running a Web client (also called a browser), the user selects a piece of hypertext connected to another text, say "Manual of Patent Examining Procedures." PA1 3. The server responds by sending text and any other media within that text (pictures, sounds, or movies) to the user's screen. In a our example, the server might provide an index to the MPEP which contains links to other documents.
2. The Web client connects to a computer specified by a network address somewhere on the Internet (say, www.uspto.gov) and asks that computer's Web server for the "Manual of Patent Examining Procedures."
The language that Web clients and servers use to communicate with each other is called the HyperText Transmission Protocol (HTTP). All Web clients and servers must be able to speak HTTP in order to send and receive hypermedia documents. For this reason, Web servers and often called HTTP servers.
The phrase "World-Wide Web" is often used to refer to the collective network of servers speaking HTTP as well as the global body of information available using the protocol.
The standard language the Web uses for creating and recognizing hypermedia documents is the HyperText Markup Language (HTML).
A good book on the World-Wide Web is "The World-Wide Web Unleashed" by John December. While "The World-Wide Web Unleashed" provides a good background for understanding the current invention, it was published after the invention was made and should not be considered prior art.
One of the major disadvantages of the HTTP protocol is that it is stateless. A request is sent from the client to the server and the server completes the entire request at once and sends a single reply message ending the transaction. It is not possible to carry on a dialog using the HTTP protocol because there is no history of previous transactions.
There have been attempts to build state information into HTTP transactions. James E. Pitkow and Margaret M. Recker describe using the hidden attribute of the TYPE field used in HTML forms. (See "Using the Web as a Survey Tool: Results for the Second WWW User Survey" to be published in the 1995 WWW Conference Report for details.) Pitkow and Recker's scheme is restricted to HTML forms and cannot be used for text web pages. Also, the forms must be computed on-the-fly imposing a great deal of overhead compared to documents which can merely be read from a file.
Another scheme encodes the user identification into the URL used to access the data. This scheme has several disadvantages. First, it defeats many caching schemes thus providing lower performance. Second, the user cannot save a particular location in his "hotlist" because there is session information in the URL.
Most people attempting to sell products using the World-Wide Web put up with the limitations of HTTP and require the user to enter her name, address, and credit card number for every item she wants to buy. Some people even require the customer to print the screen and FAX it to the store.